I have an Arduino Uno and tried this originally with no answer or solution and thought it was a hardware problem. I now have a new Arduino Mega and it gives me the same problem. I've tried every single Baud Rate in code and in the serial monitor's drop down menu.

Why am I getting random ASCII characters? This is clearly a software problem, seeing as I tried this on over 2 Arduino boards. Do I have to change the USB settings on my laptop?

Thanks, and please help with this.. This has gone unanswered for too long. Most forums with this question have it randomly start working for no reason which doesn't help me find out why.

Sorry, I wasn't home when I posted this question. The following code gives me an output of: "áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'áfr'á" endlessly with the serial monitor set to 14400 baud with newline. I tested other options in serial monitor drop down as well.

Edit: I recently purchased a Pololu Dual VNH5019 Motor controller and tested it for the first time using their arduino library downloaded here: https://github.com/pololu/Dual-VNH5019-Motor-Shield

I uploaded the "demo" example to my Mega and the serial connection worked with 115200 baud rate! This makes no sense since I tried this earlier today with a barebones program like the following without success:

I tried it again now and it works. Although no other baud rates work still. For those telling me to deal with it or just use what works, this doesn't answer my question! Why could this possibly happen... All I did was drag-n-drop the library into my arduino folder and a new baud rate works.

It appears all the answers to these questions just "randomly work"..I don't accept this

Entirely predictable That's the sequence* you get when serial monitor is set at 9600 baud.

What is the baud rate you see when you open the serial monitor? 9600, 14400? The serial monitor can be overloaded by the stuff it receives from the Arduino, and your changes will be ignored. So, in your sketch try to set a delay such as 5000 - it will not overload the serial monitor and allow you to set the baud rate. Then change again the delay in the sketch to a smaller value and see what happens.

Try this. Press and hold down the reset button on your board. Now close the serial port. Recheck that you have the correct serial port number selected in the tools menu. Then reopen the serial monitor and make sure the baudrate shown in the lower right is correct or change it if it's not. Now release the reset button.